Efficacy of Maternal and Neonatal Chemoprophylaxis for Early-Onset Group B Streptococcal Disease

OBJECTIVE: To estimate the rate of early-onset group B streptococcal (GBS) neonatal sepsis with combined maternal and neonatal chemoprophylaxis. METHODS: Since 1995, GBS chemoprophylaxis at our institution has consisted of intrapartum antibiotic prophylaxis to all women with identified risk factors. In addition, a single dose of penicillin G was administered within 1 hour of birth to all newborns without clinical signs or symptoms of infection. All neonates born between January 1, 2000, and December 31, 2008, and who developed early-onset (occurring at 72 hours of age or younger) invasive bacterial disease were identified. Incidence rates for sepsis resulting from GBS and other organisms were estimated. Compliance with risk factor identification and appropriate treatment was also ascertained. Rates of beta-lactam resistance among cases of neonatal disease caused by Gram-negative organisms were calculated. RESULTS: Ninety-four cases of early-onset GBS sepsis were identified among 143,467 live births with a rate of 0.66 per 1,000 births (0.53-0.80 per 1,000). Of available GBS sensitivities, 8.8% demonstrated clindamycin resistance, and 26.6% were resistant to erythromycin. Thirty-four cases of non-GBS early-onset sepsis were identified for a rate of 0.24 per 1,000 live births. Of available sensitivity reports, 42.1% of Gram-negative isolates were sensitive to beta-lactams. No significant difference in rates of early-onset GBS disease was found between the years 1995 and 2008. CONCLUSION: The sustained rates in early-onset GBS sepsis from 1995 to 2008, along with the low rates of neonatal disease caused by other pathogens, confirms the continued feasibility and efficacy of a combined maternal and neonatal GBS chemoprophylaxis. (Obstet Gynecol 2012; 120: 123-9) DOI:10.1097/AOG.0b013e3182592451 LEVEL OF EVIDENCE: III